Implantable prostheses are commonly used to replace or augment body tissue. In the case of breast cancer, it is sometimes necessary to remove some or all of the mammary gland and surrounding tissue, which creates a void that can be filled with an implantable prosthesis. The implant serves to support surrounding tissue and to maintain the appearance of the body. The restoration of the normal appearance of the body has an extremely beneficial psychological effect on post-operative patients, eliminating much of the shock and depression that often follows extensive surgical procedures. Implantable prostheses are also used more generally for restoring the normal appearance of soft tissue in various areas of the body, such as the buttocks, chin, calf, etc.
Soft implantable prostheses typically include a relatively thin and quite flexible envelope or shell made of vulcanized (cured) silicone elastomer. The shell is filled either with a silicone gel or with a normal saline solution. The filling of the shell takes place before or after the shell is inserted through an incision in the patient.
The development of implants having textured outer surfaces reflects an attempt to prevent the contraction of the fibrous outer capsule that forms around the implant, which tends to render an implant spherical, painful and aesthetically undesirable. Layers of polyether, polyester or polyurethane foam material have been applied to the back sides of mammary prostheses so that fibrous-tissue could grow into the material and thereby anchor prosthesis securely to the chest wall. However, possible problems exist with foam materials, which may degrade in the body over a period of time, and the effectiveness of these materials for preventing capsular contracture may disappear as they degrade.
Despite many advances in the construction of soft prosthetic implants, there remains a need for better methods for texturing surfaces of implants.